1. Melt butter over medium heat in large skillet. Add onions and mushrooms. Cook, stirring frequently, until onion is just tender, about 3-4 minutes.
2. Remove onions and mushrooms from skillet. In same skillet cook Steakums per package directions.
3. Add onions and mushrooms, gravy and wine. Cook over medium heat until everything is heated through.
4. Serve atop bread slices.